Hazard Mitigation Planning:
Tools and Techniques
I. Structural Measures
A. Alteration of environment
B. Strengthening Buildings and Facilities
II. Non-structural Measures
A. Development Management
B. Information Dissemination
III. Private Sector
Hazard Mitigation Planning: Tools and Techniques
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I. Structural Measures
A. Alteration of environment
1. Sediment-trapping Structures
a. Groins: Groins are wall-like structures, built of timber, concrete, metal sheet piling or rock,
placed perpendicular to the beach to capture material drifting along the shoreline. A groin’s
effectiveness in trapping sediment is primarily a factor of the length and the spacing of the groin
system. The appropriate length for an effective groin depends on the dominate sediment size: shorter
groins for larger grain sizes and longer groin for smaller grain size. The spacing between groins must
balance being large enough to not undermine the updrift groin and being small enough to effective
act as a sediment trap.
b. Jetties: Jetties are wall-like structures built perpendicular to the coast to stabilize channels, inlets
and outlets. While the primary function of jetties is to protect navigation channels, jetties capture
sediments by restricting the movement of materials transported by longshore currents. The critical
factors for channel stabilization are the width of the channel and management of sediment. Width of
the channel must balance being wide enough to reduce current velocity within the channel but
narrow enough to restrict shoaling. Likewise, consideration of the sediment economy plays a vital
role in the long-term viability of the channel, inlet or outlet.
2. Sediment-moving Structures
a. Beach nourishment: Beach nourishment is the artificial replacement and/or addition of sediment
to beaches. The effectiveness of beach nourishment depends on the type of imported sand, natural
slope of the beach, cross shore currents, and the frequency of storms. Consideration of natural
erosional process is vital to the long-term cost-effectiveness of any beach nourishment program.
b. Dredging: Dredging involves modification of a channel by extracting sediment. Due to the need
to dispose of extracted sediment and likelihood of future sedimentation, dredging is usually only
undertaken to maintain the navigability of channels and waterways.
3. Shoreline Protection Works
a. Seawalls: Seawalls are vertical walls built on the shoreline that are designed to protect against
direct storm wave attack. Seawalls must be constructed of durable, immovable materials to withstand
the extreme, dynamic power of storm waves. Due to the size needed to be effective, seawalls can
also be curve or stepped to dissipate smaller waves and reflect larger storm waves.
b. Revetments: Revetments are designed to protect the backshore from high tides and surges.
Revetments may be constructed out of a number of materials and configurations, from boulders
placed at the edge of a cliff or along the backshore, to securing loose material in wire gabions, to
pre-cast armor units. Revetments are more successful on lower energy coasts.
c. Bulkheads: Bulkheads are vertical walls on the shoreline, often constructed of wood or steel, and
designed to retain loose fill and sediment behind it. Since the purpose of bulkheads is to maintain the
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Hazard Mitigation Planning: Tools and Techniques
material behind it rather than provide protection from the sea or lake, bulkheads are usually not good
protection from storms or other flooding events.
d. Breakwaters: Unlike seawalls, revetments, and bulkheads, breakwaters protect the shoreline by
breaking down incoming waves to diffuse and refract the wave fronts. Breakwaters must be strong to
be effective because they receive the full force of the wave energy. Consideration of materials is
especially important for breakwaters due to the environmental forces acting on them.
e. Construction and stabilization of sand dunes: Construction of new sand dunes requires an
understanding of the biological and physical processes of the coastal zone. Most effective methods
of creating new dunes involves disrupting the airflow to encourage sand deposition, through the use
of fences made of porous materials. It is important that the fences alter the air flow but do not halt it.
Artificial dunes can also be built up by the planting of vegetation. It is important to note the
distinction between vegetation used for dune construction and for dune stabilization, as they are
usually of different species. Stabilization, as opposed to construction, of dunes is aimed at securing
bare sand surfaces against deflation. Stabilization can be achieved through grading, rapid
construction of new dunes through the use of earth-moving equipment, surface fixing by addition of
chemicals, and planting of vegetation, focusing on grasses, shrubs, and trees.
4. Flood Control Works
a. Dams and reservoirs: A dam is a structure built across a waterway to impound water. Dams, as
well as acting as flood control devises, also serve for maintaining water depths for navigation,
irrigation, water supply, hydropower and others. Dams can serve as effective flood control measures
by retaining water and releasing it at a controlled rate that does not overwhelm the capacity of the
channel beyond. Any dam or reservoir should include a spillway—a feature of a dam allowing
excess water to pass without overtopping the dam. Usually a spillway functions only in a large flood.
Storage capacity of a dam or reservoir should be a primary consideration in design and construction.
In addition, the normal sediment load on the waterway to be dammed plays an important role in the
long-term viability of the dam. Sedimentation can silt-up a reservoir and increase its volume,
decreasing its flood storage capacity.
b. Dikes and levees: Dikes and levees are often used synonymously. Dikes are usually an earthen or
rock structure built partially across a river for the purpose of maintaining the depth and location of a
navigation channel. Levees are earthen embankments used to protect low-lying lands from flooding.
Levees are built between the floodway and the structures to which they are intended to protect. The
effectiveness of a levee to reduce the threat of flood damage on structures and low-lying areas
depends on the levee being located outside of the floodway and compensating for the flood storage
displaced by it. Locating a levee (or any other structure) within the floodplain can increase the flood
height, increasing flood threat both up and downstream.
c. Retaining ponds: Retaining ponds or retention ponds are basins designed to catch surface runoff
to prevent its flow directly into a stream or river. Retention ponds are frequently a relatively
inexpensive option, provided that ample undeveloped land is available. Retaining ponds have the
added advantage of not altering the character of the stream. Retaining ponds can also act as
groundwater recharging sites and reduce water pollution through soil filtering.
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d. Flood channels: Channelization is a general term for various modifications of the stream channel
that are usually intended to increase the velocity of the water flow, the volume of the water channel,
or both. These modifications, in turn, increase the discharge of the stream, and the rate at which
surplus water is carried away. The channel can be widened or deepened, especially where soil
erosion and subsequent deposition in the stream have partially filled in the channel. Care must be
taken, however, that channelization does not alter the stream dynamics too greatly elsewhere. Flood
channels or storm sewers are installed to keep water from flooding streets during heavy rains, and,
often, the storm water is channeled straight into a nearby stream. This can become a problem by
increasing the probability of flooding downstream through greater water volume in streams than
would occur naturally. This is particularly a problem when the flood channel is cement lined, thereby
further increasing the rate at which water enters streams.
e. Floodwall: A floodwall is a reinforced concrete wall that acts as a barrier against floodwaters.
Floodwalls are usually built in lieu of levees where the space between land and the floodplain is
limited.
5. Stormwater Management: Beyond maintenance and improvement of urban storm water systems,
land treatment measures are effective means of counter-acting the effects of urbanization (particularly
the increase in impervious surfaces) on runoff. Land treatment measures include maintenance of trees,
shrubbery, and vegetative cover; terracing; slope stabilization; grass waterways; contour plowing; and
strip farming. The use of perennial vegetation, such as grasses, shrubs and trees provide cover for the
soil, prevent erosion, slow the rate of runoff and increase infiltration, and reduce water pollution.
Terracing involves a raised bank of earth having vertical or sloping sides and a flat top for controlling
surface runoff. Strip cropping is the growing of crops in a systematic arrangement of strips or bands
along a contour.
6. Drainage system maintenance: Maintenance of channels and detention basins is necessarily an
ongoing venture due to blockages caused by overgrowth, debris, sedimentation, and aging of systems.
Replacement and/or improvement of culverts, mains, stormwater lines, sewer pipes, backup valves,
etc., may be part of a general program of maintenance and improvement to reduce flooding hazards.
7. Slope stabilization: A number of potential methods are available to stabilize slopes from landslides,
including slope reduction, adding retention structures, fluid removal, and others. Slope reduction
involves reducing the slope angle, placing additional support material at the foot of the slope to
prevent a slide or flow at the base of the slope, and/or reducing the load on the slope by removing
some of the materials high on the slope. Retention structures may include ground cover and retaining
walls. The most successful retaining walls tend to be low, thick walls placed at the toe of a slide. Fluid
removal acts to reduce the role water can play in landslide by covering the surface with impermeable
material and diverting runoff away from the slope, as well as installing a subsurface drainage system.
Other methods include cementing the slide material, bolting a rock slide, and the driving of vertical
piles into the foot of the slope.
8. Brush clearing, controlled burns, fuels breaks: Brush clearing, controlled burns, and creating
fuels breaks are all ways of mitigating the threat from wildfires by reducing the material that can be
burned and the area in which it can spread.
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Hazard Mitigation Planning: Tools and Techniques
9. Wetland preservation: Wetlands are areas that are normally inundated with water. Many important
ecological communities are found in wetlands, including bottomland hardwoods, swamps, marshes,
bogs, sloughs, potholes, wet meadows, river overflow, mud flats, and natural ponds, and are essential
for a number of species of fish and wildlife. Wetlands act as flood control by storing tremendous
amounts of floodwaters, slowing and reducing downstream flows. Wetlands also play an important
role in coastal productivity and the cycling of river-borne material (pollutants included) by acting as a
biogeochemical filter.
B. Strengthening Buildings and Facilities
1. Strengthening Buildings
a. Floodproofing: Floodproofing can be done in two ways: dry and wet. Dry floodproofing involves
the sealing of a building against floodwaters by making all areas below the flood protection level
watertight. This can be done by coating walls with waterproofing compounds or plastic sheeting and
protecting building openings with removable shields or sandbags. Dry floodproofing is limited to 2
or 3 feet above the foundation of the building due to the pressure exerted by deeper water on the
walls and floors. With wet floodproofing, floodwaters are intentionally allowed to enter a building to
reduce the pressure exerted by deep water. Wet floodproofing at minimum involves the removal of
some valuable items and extends to the rebuilding of floodable areas. Wet floodproofing can
dramatically reduce damage costs by simply removing furniture and electrical appliances out of the
floodprone area.
b. Elevating: Elevating a building is the raising of that building above the flood level. This is the
one of the best techniques for protecting buildings that are, or for some reason must be, located in
areas prone to flooding. Elevation is cheaper than relocation and is less disruptive to the
neighborhood. Effective elevation should take in consideration the need to wet floodproof everything
still located in the floodprone area, such as basements or garages.
c. Windproofing: Windproofing focuses on design and construction of a building to withstand wind
damage. This involves the aerodynamics of a structure, materials used, and addition of features such
as storm shutters.
d. Basement protection: Basement protection may involve floodproofing of the structure, both wet
and dry, as well as building a barrier around the opening to the basement to protect it from
floodwaters.
e. Seismic retrofitting: Seismic retrofitting involves adding braces, removing overhangs, and
providing flexible utility connections and tie downs to reduce damage.
2. Strengthening Facilities
a. Floodproofing: Floodproofing can be done in two ways: dry and wet. Dry floodproofing involves
the sealing of a facility against floodwaters by making all areas below the flood protection level
watertight. This can be done by coating walls with waterproofing compounds or plastic sheeting and
protecting facility openings with removable shields or sandbags. Dry floodproofing is limited to 2 or
3 feet above the foundation of the facility due to the pressure exerted by deeper water on the walls
Hazard Mitigation Planning: Tools and Techniques
5
and floors. With wet floodproofing, floodwaters are intentionally allowed to enter a facility to reduce
the pressure exerted by deep water. Wet floodproofing at minimum involves the removal of some
valuable items and extends to the rebuilding of floodable areas.
b. Burial: Burial can play an important role in protecting necessarily utility connections, particularly
during high winds and ice storms.
c. Elevating: Elevation of facilities is the raising of the facility above the flood level. Of particular
importance for facilities is the elevation of electrical and mechanical equipment. It may not be
possible to effectively raise many facilities, but by elevating electrical and mechanical equipment,
the facility should be able to recover quicker after a disaster.
d. Seismic retrofitting: Seismic retrofitting involves adding braces, removing overhangs, and
providing flexible utility connections and tie downs to reduce damage.
e. Improvements to stormwater/wastewater/water treatment facilities, pump stations:
Improvements to stormwater, wastewater, water treatment facilities, and pump stations should be
undertaken to minimize threat from flooding and other disasters. Capacity of these systems should be
evaluated and, if necessary, increased to meet realistic demands.
f. Upgrading piers/wharves: Wharves and piers should be upgraded and retrofitted to match the
storm forces they are exposed to.
g. Repair/reconstruction of fuel storage tanks: Fuel storage tanks need to be inspected and if
necessary, repaired or reconstructed in the event of flooding or earthquake.
h. Storm shutters: Storm shutters are an important defense against high winds. Storm shutters
protect a facility by preventing winds from entering a building and possibly damaging it.
3. Building Codes: Building codes are laws, ordinances, or governmental regulations setting forth
standards and requirements for the construction, maintenance, operation, occupancy, use or appearance
of buildings, premises, and dwelling units. Building codes should be designed to ensure that
development is built to withstand natural hazards. Regulatory standards should created for the
following:
a. Freeboard
b. Foundation Design
c. Wind Standards
d. Cumulative Substantial Improvement
e. Lower Substantial Improvement
f. Critical Facilities
g. Enclosure Limits
h. Electrical and Mechanical Equipment
II. Nonstructural Elements
A. Development Management
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Hazard Mitigation Planning: Tools and Techniques
1. Planning
a. General comprehensive planning: Comprehensive plans and land use plans identify how a
community should be developed and where development should not occur. Uses of the land can be
tailored to match the land’s hazards, typically by reserving hazard areas for parks, golf courses,
backyards, wildlife refuges, natural areas, or similar compatible uses. Generally, a plan has limited
authority. It reflects what the community would like to see happen. Its utility is that it guides other
local measures, such as capital improvement programs, zoning ordinances, and subdivision
ordinances.
b. Storm hazard mitigation and post-storm reconstruction plans: A locality should develop a set
of policies or planning instruments to have in place to facilitate post-storm decision making. This
allows for substantial amount of decision-making to occur prior to the disaster event and permits
better decision-making after the event. Storm hazard mitigation and post-storm reconstruction plans
should identify priorities both for reconstruction and mitigation.
2. Development Regulations
a. Zoning: Zoning is the division of a jurisdiction into districts and the prescription of uses for
which buildings within designated districts may be put—their lot size, yard size, etc.
i) Overlay zones: These zones coexist with other zones, operating like a transparency overlaying
existing land use controls. Examples include floodplain and historic districts; within these areas
development is regulated by the standard zoning ordinance and the unique requirements of the
overlay zone.
Overlay zones allow communities to isolate and protect areas not covered by the rest of the
ordinance. However, like any zoning, the protections of overlay zones can be changed or removed.
ii) Agricultural zones: This zoning category sets a minimum lot acreage calibrated to the size
necessary to maintain a commercial farm (which varies depending on the predominant crops
grown in the region). Some ordinances contain a prohibition on non-farm uses (exclusive use).
An unintended consequence of the diminution of property value is that farmers are
deprived of the collateral necessary for financing, making farming unfeasible. Non-exclusive use
leads to renting, which does not induce major improvements in the land. A lack of such
improvements reduces the viability of farming in the larger area, which in turn creates pressure to
allow development. Finally, as with any zoning, this category must allow some reasonable
economic use.
iii) Contract or conditional zoning: Under both approaches the landowner agrees to previously
unstated conditions (which can be in the form of deed restrictions) in exchange for some
government action (such as a rezoning) or an exemption from other conditions. The difference
between the two is that with contract zoning the government is contractually obligated to allow the
use.
The purpose of these techniques is to provide flexibility in dealing with a small number of
land parcels, but they can nevertheless be unpopular with developers. Contract zoning is
vulnerable to an ultra vires challenge (the government has impermissible delegated its authority),
Hazard Mitigation Planning: Tools and Techniques
7
and both can be challenged under uniformity provision (that all land in zoning district be subject to
the same restrictions), as spot zoning, or as contradicting a comprehensive plan.
iv) Special exception: This term, which is often used interchangeably with conditional use, is used
for activities which are permissible but require an additional layer of approval because they need
additional attention or cannot be reasonably accommodated in a traditional zoning ordinance. In
some cases the use can be by right if the developer meets certain conditions.
While designating most uses as special exception may be illegal, the application of the
technique against all new development has been upheld when used in connection with interim
zoning or if the jurisdiction already had an adequate facilities requirement.
v) Bonus and incentive zoning: In exchange for concessions from a developer, some
governments allow developers to exceed limitations imposed by current regulations, such as
building height or dwelling unit density.
This technique has not seen much use outside of non-metropolitan areas. While similar to
the accepted practice of dedication, bonuses and incentives may be vulnerable as contract zoning,
and the extent of the connection needed between the concession and the government purpose is
not clear.
vi) Floating zones: These zones appear in the text of zoning ordinance, but not on the map, and
are typically used for shopping centers, industrial areas, mobile home parks, or multi-family
housing.
While the location of floating zones can be subject to special interests and politics, they
are usually based on facts, as opposed to speculated future needs. They may be vulnerable to a
challenge of giving too much discretionary power or as spot zoning.
vii) Density transfers/ average density/ cluster: This type of regulation allows flexible design of
large or small scale developments that are constructed as a unit; the actual design is matter of
negotiation, but the basic premise is that some areas are developed more intensively than would
normally be allowed, while others are used less than what the market would determine. The type of
development usually has to conform to zoning, but there is a trend toward allowing mixed use.
The government’s goal for this designation is to create open space, protect sensitive
features and/or allow farming to continue, while the developer benefits for the higher dwelling unit
density or floor area ratios. One consequence can be a form of leapfrog development, with its more
expensive public services. Some farm-related uses may be incompatible with residential
development, and development can lower farming activity below a critical mass.
viii) Performance or impact zoning: Rather than enumerating permitted uses, performance
zoning sets standards for the effects or level of impact allowed for development. The standards
may govern traffic, runoff, or viewsheds. The ordinance could theoretically allow any use as long
as it met the requirements, but in practice most performance controls are used in conjunction with
traditional zoning.
The level of expertise and size of the staff required to implement the standards depends on
their comprehensiveness and how much of the jurisdiction they encompass. Performance zoning
gives developers greater flexibility, but in some cases it may make enforcement more difficult. In
addition, some impacts are difficult or impossible to quantify.
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Hazard Mitigation Planning: Tools and Techniques
ix) Urban growth boundary: Urban containment basically involves designating a perimeter
around an urban area. Urban development is encouraged within the line and discouraged beyond
it, generally by restricting land to resource use and very low density residential development and
precluding the extension of urban services. The area within the perimeter is designed to be
sufficient to accommodate the area’s growth for a specified period.
The objective of urban containment is to promote compact and contiguous development,
to preserve resource production lands, open space, and sensitive areas, and create a clear boundary
between urban and rural areas. If the area is too large, the boundary may not achieve its goal of
compact development; if it’s too small, property values may increase dramatically.
x) Specific development plans; shadow platting: This technique creates a plan which describes
land uses and subdivisions in greater detail and covers a smaller area than a comprehensive plan,
zoning map, or public facilities plan. The plan may include designation of specific uses and/or
design standards that vary from the zoning ordinance and may even contain enough detail to allow
approval of developments which comply without public hearing.
The objective of these plans is to preclude inefficient land use in areas designated for
future growth at urban densities. The plans can also create neighborhood identity, coordinate
development of different properties, and establish a fast track for development approvals.
xi) Total population limits; development caps: As the name implies, these are absolute limits on
housing units or population itself. If a limit succeeds in limiting growth but demand for housing is
high, property values will necessarily increase, which can affect the character of the community.
The limits themselves do not address quality, type and location of growth, and restricting only one
development sector can lead to an imbalance of growth. Not surprisingly, a restriction on growth
can cause development to leapfrog out to neighboring jurisdictions.
xii) Rate allocation systems; growth phasing: Allocation systems and growth phases specify a
rate of growth, which can be a percentage of total growth or a set number of units or square
footage allowed per year.
These techniques are versatile, as they can be used to address quality, type and location of
growth. In some cases developers compete for points which allow them to build. The points are
based on criteria deemed desirable by the community, such as open space preservation, but the
competition itself can be complex and time consuming to administer. If the rate or phases are
slower than the market, property values will necessarily increase, which can affect the character of
the community. A slower than market rate can also cause growth leapfrog out to neighboring
jurisdictions. Applying the phases to less than all development sectors can lead to an imbalance of
growth. The rates or phases can be used to ensure the adequacy of lumpy investments, such as
water treatment plants, which serve the entire community and cannot be provided incrementally.
xiii) Mandatory low-income housing construction ordinance: These ordinances require those
developing large residential projects (often over 50 units, sale or rental) to include a certain
percentage of subsidized or low-cost housing (typically 10 to 15 percent of the total number of
dwelling units). This requirement can be made economically feasible by tying it to the availability
of federal subsidies or tax credits, or increasing allowable densities.
In addition to increasing the stock of lower income housing, these ordinances seek to
avoid concentration and improve housing quality. In order to be effective the area needs to have
growth pressures, a relatively high rate of return development, and there should be little
Hazard Mitigation Planning: Tools and Techniques
9
opportunity to serve the same market by simply building in a jurisdiction without a low income
ordinance. These ordinances may face substantial due process challenges.
xiv) Local environmental impact ordinances: Reports to local governments on environmental
impacts generally mention alternatives, mitigation strategies, and irreversible changes.
By forcing developers to account for their environmental values, local governments gain
the authority to encourage environmentally sound land use practices. To be effective, the local
government must have the technical capacity to review the impact statements.
3. Land and Property Acquisition
a. Fee-simple acquisition of undeveloped land: Fee-simple acquisition of undeveloped land
includes the purchase of the full “bundle of rights” contained in real property. Fee-simple
acquisition of undeveloped land is important for two reasons. First, it can involve removal of
hazardous sites from the private market, thereby reducing potential threat to the public. Second,
fee-simple acquisition can act as a development management tool for guiding the location of
development. Fee-simple acquisition can be prohibitively expensive, leading localities to
alternative ways to finance and manage property, such as land banking and use of restrictive
covenants.
b. Relocation of existing development: Relocation of existing development is the surest and
safest way to protect it from hazardous threats. However, relocation can become more problematic
if the buildings are large and heavy, making a move difficult. Relocation can also be very
expensive, especially when there is a large amount of development in the hazard prone area.
c. Purchase of development rights/easements: The owner of an easement has one or more of the
several rights in land, leaving the rest in the hands of the land owner. Easements either grant an
affirmative right to use property, such as a right of access, or restrict the land owner’s right to use
the property in a particular way. Local governments can purchase an easement in development
rights and thus preclude building on the property.
By owning the development rights, the government has a very high level of control while
allowing the land to remain in private hands. However, the government does lose money twice: in
the purchase and foregone tax revenue from the reduced property value. The government must also
police the easement, since unenforced rights may eventually be forfeited.
d. Transfer of development rights: These programs treat development as commodity separate
from land itself. The government awards development rights based on value or acreage of land,
and establishes sending and receiving areas for these rights. The sending areas contain land the
government, for various reasons, seeks to protect. In these zones landowners do not have enough
rights to develop their land, but they can sell rights to developers in receiving areas. With these
rights projects can take on higher densities than would otherwise be permissible. In addition to
density, TDR programs can be used to affect the type of uses if the rights are for specific kinds of
development, as opposed to one general purpose right.
Besides protecting sensitive areas, TDR programs are supposed to reduce the land value
shifts of zoning by compensating those who can’t fully develop their land. However, it is a
complex system, which makes it difficult for planning staffs to implement and landowners to
understand and accept. TDR programs alone cannot ensure quality development or that there will
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Hazard Mitigation Planning: Tools and Techniques
be a critical mass of resource operations (for example, that there will be enough farms to support
the area’s feed stores). Perhaps most importantly, the region must have enough development
pressure to make the rights marketable.
e. Advance site acquisition (land banking): This technique involves the purchase of land by the
government for eventual use or resale to the private sector in order to influence the character
and/or timing of growth.
While on the surface land banking may seem simple, there are several potential problems,
limitations and reasons for opposition: the public sector, rather than private landowners, receive
the benefits of property value increase; value of land outside the land bank may be reduced
because it eliminates the possibility of developer-contrived scarcities, and the government may sell
land at below market prices; it requires high level of expertise on the part of planning staff;
bridging the gap between revenues from sale of land and purchase of the land may require debt
financing, which will create pressure to increase sale prices; the problems addressed by land
banking are often regional, and thus beyond the power of most jurisdictions.
f. Purchase sellback/leaseback: The government can control the use of its land by selling or
leasing it to the private sector with restrictions, covenants and/or negative easements.
In so doing the government maintains control without having to actually manage the
property. Though less involved than management, the leasing or selling authority does need to
ensure compliance with the terms of the agreement. Where the government sells the property, the
restrictions lower the tax burden on the owner.
g. Purchase option (right of first refusal): A right of first refusal guarantees the government the
first opportunity to purchase the property, while an option prevents the sale of the property to
another party for specified period.
If the budget does not have room for an outright purchase, this can be an effective
protection, but it can also be an unnecessary expense if the government will buy the property
anyway. In addition, the property may become more expensive in between buying the option or
first refusal right and the actual purchase. On the other hand, designation of future acquisition may
reduce the property value, possibly making the government liable for damages if it does not go
through with the purchase.
h. “Sword of Damocles” provision: A government agency with the power of eminent domain
suspends condemnation of land covered by a comprehensive plan as long as the land use remains
compatible with the plan. If the landowner proposes or commences a use in contravention of the
plan, the land is taken into public ownership.
The federal government has used this approach in Idaho’s Sawtooth National Recreation
Area. These provisions allow land to remain in private ownership and are an effective, inexpensive
protection tool in the short run. However, increasing land values may encourage property owners
to develop incompatible uses and make the cost of condemnation prohibitive. If on the other hand,
land values are suppressed by the provisions, governments may face political pressure to remove
them.
Hazard Mitigation Planning: Tools and Techniques
11
4. Taxation, Fiscal, and Other Incentives
a. Differential assessment/taxation: This technique can take on several different forms: reducing
the tax rate applied to the assessed value of resource production land such that payments only
cover essential services; reducing the assessed value of resource production land such that
payments only cover essential services; reducing the assessed value of land to a percentage of
urban land; assess the value based on current income-producing capacity, as opposed to the market
value (most states allow land in several specified uses, such as forests and open space, but some
limit to farmland).
The differential assessment reduces the tax burden on land facing development pressure
and recognizes that some tracts put less demand on services funded by property taxes. The flip side
of this recognition is that the loss of tax revenue can be substantial. An unintended consequence of
having preferential status is that it can be a haven for speculation as property value rises, and can
force development further out as close-in property owners hold out and sustain tax benefits. This
effect can be reduced with either a use change/conveyance penalty, or a deferred taxation system,
where the difference between market and preferential taxes are paid when the property is
converted to a higher use (laws vary, but the range is five to ten years of tax deferred taxes due).
However, the amount of accumulated taxes may not be enough to offset profits, and there may be a
leapfrog effect because land farther out will have lower market value and thus lower accumulated
taxes. In addition, basing the tax rate on income production for a specific property will encourage
development of best farmland because it will have the lowest accumulation of deferred taxes
(which can be avoided by having a uniform rate). The few legal challenges have been based on
uniform taxation provisions in state constitutions.
b. Land gains taxation, transfer or development taxes: Vermont is the only state to employ a
tax on the profits gained from the sale of land. The amount is inversely proportional to the length
of time land is held, and it can apply only to value of land, not improvements. There is an
exception for the principal residence of seller. Transfer taxes are simply assessed against the seller
of land devoted to certain designated uses. Development taxes are charged against developers
obtaining permits to convert land in certain categories to more intense uses.
These taxes discourage conversion to higher density, slow the growth rate, and discourage
speculation, but they also are not effective for long term protection and may limit needed economic
development while owners hold out on selling their property. The land gains tax may be
vulnerable to legal challenge under the uniformity clause in state constitutions or based on
discrimination against non-residents because of the principal residence exception. On the other
hand, the Vermont law sustained a Fourteenth amendment challenge of arbitrary discrimination
against land owners of less than six years.
c. Special assessments districts: Special assessment districts include property owners who benefit
from a specific public improvement. These owners are charged a fee, which can be based on an
attribute(s) of the property that is proportional to the benefits received from the improvement, and
is charged to both new and existing development. There are numerous possibilities, from
temporary creations designed simply to raise revenue for a specific improvement to independent,
special purpose governmental entities. A commonly used example is the transportation utility fee.
While exactions, bonds, impact fees and other methods are used to pay for transportation
improvements, the utility fee covers the maintenance/operation cost of the system(s).
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Hazard Mitigation Planning: Tools and Techniques
Since this is not a tax, special assessment districts are free from constitutional
requirements of uniformity, equality and double taxation. This technique shifts the financial
burden from the general public to those directly benefiting. The revenues are more predictable
than sources which depend on development cycles, which makes issuing bonds easier.
d. Impact fees/system development charges: These assessments are typically one time, up front
charges (some jurisdictions allow extended payments) against new development to pay for off-site
improvements. The fees can also be set up to have growth buy into existing services with excess
capacity. Two specific examples of impact fees are: 1) Family Reservation Fees—where
developers pay up front for their proportionate share of future improvements or expansions, and 2)
Linkage Fees—where non-residential development finances needs linked to the new development,
such as affordable housing.
Impact fees can fund wider variety of services than exactions or special districts, and can
cover the full costs of improvement, unlike land dedication requirements. On the other hand,
impact fees do not help with maintenance costs. They are typically used in place of negotiated
exactions, which take longer and are less predictable or equitable. Finally, every impact fee must
meet a three part legal test: 1) need for improvements is created by new development, 2) the
amount charged the new development is proportionate, 3) all revenues must be spent in proximity
to the new development and within a reasonable period of time.
e. Development impact tax/improvement tax: These are taxes on new construction, including
alterations to existing structures, usually paid while applying for building permit.
Unlike a fee, this charge does not need to be based on the cost of improvements needed to
serve the new development, and there are no restrictions on how the revenues can be spent.
f. Developer Exactions: These are private sector investments in public infrastructure needs
created by new development. Exactions can take the form of on or off site improvements or land
dedication, and are often a condition for approval.
There needs to be a rough proportionality between the exaction and the development’s
impact. For this reason land dedications are good, as they have a close relationship to the
development, but dedications don’t cover the cost of improvements. Negotiated exactions do allow
financing of improvements and can be very specific, but they also create problems: improvements
usually reflect the needs of individual developments and not the community as a whole; they are
not predictable; particular geographical conditions or bargaining ability may make some exactions
appear inequitable; small developments may not be subject to the same kind or degree of exactions
as large ones, even though they can have the same or greater cumulative effect; exactions do not
cover maintenance costs.
5. Capital Facilities Policy: This technique creates a timetable and budget of when, where, and what
level of municipal services a government will supply.
The timetable controls growth because it is rarely feasible for a developer to provide services,
and capital programming is less expensive and less likely to face legal challenges than many other
growth management techniques.
a. Focused public investment plan (FPIP): Basically a Capital Improvements Plan for a specific
area, known as a Public Investment Area (PIA). A Focused Public Investment Plan (FPIP)
coordinates and concentrates investments such as water, sewer, streets, schools and parks. While
Hazard Mitigation Planning: Tools and Techniques
13
funding mechanisms and expected contributions from developers may vary, the objective is to
supply fully served land for development.
FPIPs limit growth which is dispersed and has inadequate public services. PIAs allow
governments to choose which parts of the jurisdiction are suited for growth, which can include
areas free of environmentally sensitive features and infill/redevelopment sites. Carefully chosen
PIAs will also minimize the overall cost of providing services. FPIPs make it easier to create a
system of development charges which is equitable and understandable to the developer.
b. Service areas: The taxing authority of a government can designate areas which will receive
services and those that will not, and tax the former at a higher rate.
This technique will be more effective if used in conjunction with a regulatory program
which limits development in areas with lower, more attractive tax rates, and a capital program will
make the designation more equitable and less open to legal challenge. (The uniformity of taxation
provision in most state constitutions can be the basis for legal challenge.)
c. Marginal cost pricing: Under this system new development is responsible for the incremental
cost of the service needs it creates (for example, paying per foot for water and sewer) as opposed
to average cost pricing (charging the same regardless of real costs). The latter form of pricing
creates an incentive for low density growth away from existing services, since it is effectively
subsidized higher density, close-in development.
The complexity of marginal cost pricing leads to the creation of price districts instead of
pricing each development, which can lead to a problem at the district borders; people will
understandably ask why they have to pay more than their next-door neighbor.
d. Concurrency/Adequate public facilities requirement: This is a required level of municipal
services that must exist when the proposed development is completed or within a certain period
afterward.
The requirement can have the effect of encouraging development in areas already well
served by public facilities, and/or shifting development to jurisdictions with lower service
requirements. Demanding service requirements also may discourage certain types of development,
especially high density.
6. Land Use Policy: The above development management tools should be incorporated into well defined
policies (such as expressed through a comprehensive or land use plan) that address the location, density
and use of land, paying special attention to high risk areas. Development should be located away from
high hazard areas. Density should reflect the impacts of development on the environment, as well as the
ability of local government to protect the community, and need to evacuate the area. Use of land should
be also be reflective of the impacts on the environment and reduction of hazards.
7. Moratoria: A moratorium is a short-term suspension of right to develop, usually done by not issuing
permits. Moratoria can play an important role following a disaster, to set priorities for response and
potential mitigation efforts.
8. Reconstruction Triage: Reconstruction triage is the sorting of priorities for reconstruction. The use of
a triage for decisions on reconstruction should be outlined in a post-disaster reconstruction plan, created
prior to the disaster.
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Hazard Mitigation Planning: Tools and Techniques
B. Subdivision Regulations: The division of a lot, tract of parcel into two or more lots, tracts, parcels, or
other divisions of land for sale or development.
C. Information Dissemination
1. Real Estate Disclosure Requirements: Real estate disclosure requirements would require notification
that the property to be purchased is located in a hazard prone are notified of this. Currently, federally
regulated lending institutions must advise applicants for a mortgage or other loan that it is to be secured
on a building which is in a floodplain as shown on the Flood Insurance Rate Map. Since this requirement
has to be met only five days before closing, often the applicant is already committed to purchasing the
property when he or she first learns of the flood hazard. State laws and local practices by local real estate
boards can overcome this deficiency and advising newcomers about the hazard earlier. They may also
require disclosure of past disaster events, regardless of whether the property is in a mapped high risk
zone. Terms and maps of used for disclosure of hazard risk should be meaningful to homebuyers.
2. Community Awareness Programs: Community awareness programs may be used in conjunction
with and/or in place of real estate disclosure requirements to directly educate the potential homebuyer
and the community of hazard risks. Information can be presented in a number of ways, including
information pamphlets, brochures, literature and workshops. Topic may include identification of hazards,
things to consider in purchasing a home or business, ways to limit exposure and reduce future property
damages.
3. Hazard Disclosure
a. Mapping Hazards: The application of vulnerability and/or risk analysis, inventories, and other
studies to maps is an important step in reducing disaster potential. Locating hazards can be
accomplished through cooperation with a number of federal and state agencies. Use of a geographic
information system to overlay high risk areas over property maps can serve as indicators of sites for
mitigation.
b. Notification: Notification of the locations of hazards and the risks needs to be given to public
officials, public employees and agencies, the general public, and the private sector. Notification can
be given through workshops, information pamphlets, brochures, literature, etc. It is important that
information on the location of hazards is shared between agencies to ensure better decision-making.
4. Disaster Warning: The first step in responding to a potential disaster is to know that one is coming.
This may require monitoring of local conditions. Disaster warnings can be administered in a number of
ways, including via sirens, radio, television, cable TV, mobile public address systems, telephone trees,
and even door-to-door contact. Multiple or redundant warning systems are most effective, as the message
will received even if one part of the warning system is not heard.
5. Workshops: Workshops can play a valuable role in preparation for a disaster. Workshops can be
arranged for public employees and/or state agencies, for general public, and for public officials. These
workshops should include education regarding the potential hazards, possible mitigation steps that can be
taken, and how to respond after a disaster occurs.
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6. Education and training: Education and training for awareness of hazards, mitigation steps, and
disaster response should not only be targeted to public employees, agencies, and public officials, but
should also include the general public and the private sector.
III. Private Sector
A. Lending: The application of a real estate disclosure requirement or other information to lending
sources regarding the risk of development in hazard prone areas would reduce to cost of lending both to
the lending institutions and consumers of their services. It is important that lending institutions
understand the risk of supporting development in high risk areas.
B. Insurance: The insurance industry plays an important part in the private sector guiding of
development. The National Flood Insurance Program is a good example of how the insurance industry
can also play a role in promoting development that reduces hazard risk.
C. Building Industry: The building industry should be educated to the structural and building codes
designed to reduce damage from hazardous events. The building industry should also be educated on the
location of high risk areas and ways to mitigate hazardous threats.
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Hazard Mitigation Planning: Tools and Techniques